Due to his success in the 2011-2012 Proleague Season 2, Jaedong would be one of the two KeSPA Code S seeds for the 2012 GSL Season 4.[5] He was chosen by MC to play in his group, Group C, together with Curious and MarineKing and made his GSL debut on Wednesday, September 5. He would disappointingly go 0-2 in his group, winning only a single game against MarineKing and drop down to Code A. There, in his first match against finale, Jaedong would lose 0-2 to drop out of Code A and end his GSL debut.

Jaedong sprang back in the following GSL season, however, as he qualified for Code A after going through the brutal preliminaries. Jaedong beat Shuttle, Shine and PuMa to make it back into the GSL, only dropping a single game throughout his preliminary run. He then went on to defeat Sirius 2-1 in the first round, and LosirA 2-0 in the second. He faced Hack in the round of 24 for a Code S spot, but ultimately lost 1-2. In the Up and Down Matches, Jaedong was grouped with his Brood War rival Flash, and ended up beating him in their match. Despite ending the night with the same score as Flash, Jaedong's head to head win allowed him to place ahead of his rival, and secure third place for a shot at Code S via the Wildcard tournament. He was barely unable to qualify in the Wildcard matches, tying ByuN in map score but losing the head-to-head game. He subsequently fell out of GSL, losing to Lure in the first round of Code A.

On the 5th of December 2012 it was announced that Jaedong would be joining North American team Evil Geniuses.[6] He participated in the 2012-2013 Proleague as part of the EG-Liquid alliance. He had a fairly lackluster season, going 19-23, and more notably 6-14 against Protoss. Compared to Flash, who led the league with 44 wins, his poor team league performance stood out even more.

At the WCS 2013 Season 2 Finals, Jaedong had impressive results against Protoss opponents, with twelve map wins and only two losses in the group and bracket stages. However, meeting a strong Terran player in the finals once again in Bomber, Jaedong was unable to overcome the relentless 3-base aggression of his opponent and lost 0-4 for the second tournament in a row, and took second place in his fourth consecutive finals.

A Taste of Victory (December 2013 – Present)

After 5 second place finishes in premier tournaments, Jaedong finally emerged victorious at ASUS ROG NorthCon 2013. After defeating StarDust and Nerchio in the group stage, he bested elfi and INnoVation to reach the finals against foreigner hope Scarlett. A close series ended with Jaedong winning over Scarlett 4-2, thus ending Jaedong's streak of silver medals and granting him the title of the first StarCraft: Broodwar champion to win a premier tournament in StarCraft II.

Historically Jaedong's weakest matchup in StarCraft II, his ZvP has once more shown weakness in 2014, while his ZvZ remains among the best in the world. Facing only Zerg players in the playoffs, Jaedong was nevertheless defeated by Impact at the 2014 DreamHack Open Bucharest, and had to settle with a 3rd-4th place finish alongside INnoVation.

Jaedong was able to claim another championship from Lone Star Clash 3 in May. Jaedong faced State and Heart in Group C of the group stage matches and advanced out as first with a 2-0 score. He then went on to advance into the playoffs. In the quarter-finals, he had a close 3-2 series victory vs Stephano. This match was significant due to the fact that both players were very famous and well known for their own reasons, and many people were eager to see if Stephano had what it took to take down Jaedong after being gone from the competitive scene for almost five months. After defeating Stephano, Jaedong's next opponent, viOLet didn't give him much trouble as Jaedong went on to easily 3-0 viOLet and advanced into the finals to face Polt. After a fantastic series, Jaedong took a 4-2 victory and claimed his first championship for SC2 in 2014.

Jaedong would participate at HomeStory Cup IX where in the first set of groups he was able to beat Socke and fellow Korean player YoDa to advance. In the Round of 16 Jaedong was pitted against MC, HasuObs, NightEnD. Jaedong would defeat NightEnD 2-0 and HasuObs 2-1 to once again advance to the Playoff bracket. His opponent would be Korean Terran Player TaeJa whom many considered one of the strongest Terran players around, despite a close fought series Jaedong would end up losing 2-3 knocking him out of the tournament.

Trivia

In May 2010, Lee Jae Dong was selected as a South Korea representative for the WCG 2010 Torch Relay.[7]

There are two common South Korean nicknames for Jaedong: 폭군 (Pok-kkun, 'The Tyrant') and 파괴신 (Pagoesin, 'The God of Destruction' or 'Destructor'). The nickname ‘Tyrant’ was coined by OGN commentator Um Jae Kyung because Jaedong's hyper-aggressive style set him apart from other Zerg players. 'The Legend Killer' was a nickname given to Jaedong by the Western community.[Citation needed]